I found this pinknews article which claims Frisk from Undertale is confirmed non-binary, but in the cited interview Toby Fox actually just straight up refuses to answer the question. which is... the opposite of a confirmation

wtf?

(if you know an actual source, lmk)

https://www.pinknews.co.uk/2021/02/17/non-binary-video-game-characters-bloodhound-apex-legends-lgbt-gaming-fl4k-borderlands-3/

https://web.archive.org/web/20190108081443/http://outermode.com/interview-toby-fox-undertale